The invention relates to an image resolving detector arrangement with an image resolving detector having a two-dimensional array of detector elements and an imaging optical system, which generates an image of an object scene on this image resolving detector, and image element selection means, by means of which radiation of respectively one of several adjacent image elements of an image area associated to the detector element is directed consecutively onto each of the detector elements.
Such an arrangement is known from U.S. Pat. No. 5,519,206. This patent describes a passive image resolving detector arrangement having a matrix detector, on which an image of an object scene is generated by imaging optical means and which consists of a two-dimensional arrangement of detector elements. A micro-mechanical mirror raster with a two-dimensional arrangement of mirror elements is provided. Each mirror element is pivotable into first and second operative positions by binary control signals. The object scene will be imaged with high resolution onto the micro-mechanical mirror raster by a first imaging optical system. The micro-mechanical mirror raster will be imaged on the matrix detector by a second optical system in that way that one sub matrix of the micro-mechanical mirror raster with a plurality of mirror elements will be imaged onto each detector element. In their first operative positions, the mirror elements direct the imaging beams past the matrix detector, while, in their second operative positions, they direct the imaging beams onto each associated detector element of the matrix detector. The micro-mechanical mirror raster is controlled such that in cyclic sequence pre-determined mirror elements of the sub-matrices are in their second operative positions and the other mirror elements of the sub-matrix are in their first operative positions.
In this way, images of one pixel each per sub-matrix will be generated consecutively by the matrix detector. These images may then be interspersed xe2x80x9celectronicallyxe2x80x9d in a memory. An electronic image results, the resolution of which is not determined by the matrix detector but by the mirror raster.
European patent 0,133,890 discloses an electro-optical detector system for generating electronic image information. This detector system has a charge coupled matrix detector consisting of an arrangement of rows and columns of square detector elements. Interspaces between the detector elements have a width which is substantially equal to the side length of the detector elements. An image of the object scene is moved step by step relative to the matrix detector to the corners of the square by a wobbling mirror which is consecutively stepped on into four positions, the path of rays of the image beam being reflected by this wobbling mirror. Thereby each detector element cyclically detects consecutively four adjacent areas of the image of the object scene. In a computer, the image information is then assembled to a continuous xe2x80x9cimagexe2x80x9d.
It is the object of the invention to improve the resolution of a detector arrangement by simple means.
To this end, an image of an object scene is generated on a two dimensional array of detector elements by an imaging optical system. A micro-light stop raster, of which each micro-light stop defines an aperture, is arranged in an image plane of this imaging optical system. Each of these micro-light stops is associated with one of the detector elements. The micro-light stop raster is moved step-by-step in this image plane to a number of discrete positions. In each position, each micro-light stop aperture permit radiation from only a part of the image area associated with the respective micro-light stop to fall on the detector element.
In this way, the resolution of the detector arrangement is defined by the dimensions of the micro-light stop raster instead of the dimensions of the detector element raster. Each detector element covers a plurality of smaller picture elements, the size and spacing of these picture elements being defined by the size of the light stop aperture and the steps carried out by the micro-light stop raster. This is achieved without having to deflect the path of rays by mirrors, as with the prior art discussed hereinbefore.
Further objects and modifications of the invention will be apparent to those skilled in the art, when reading the following description of preferred embodiments of the invention.
Embodiments of the invention will now be described in further detail with the reference to the accompanying drawings.